Danger and Usefulness affect word recognition (e.g., Wurm & Vakoch, 2000), and a related construct affects memory (e.g., Nairne, Thompson, & Pandeirada, 2007). We tested hypotheses about differential effects of these dimensions, based on the relevance of concepts relative to the time perceptual systems underwent selection pressures. In two experiments participants made auditory and visual lexical decisions for nouns rated on Danger, Usefulness, and “Ancientness.” Danger interacted with Ancientness in both auditory and visual processing. Increasing Danger led to faster RTs and better accuracy only for words judged to have ancient relevance. Interactions with participant gender were seen in both auditory and visual analyses. Consistent with Wurm, Whitman, Seaman, Hill, and Ulstad (2007), men’s but not women’s auditory performance improved with increasing Danger. The beneficial effect of Usefulness on accuracy was greater for women than for men in both experiments. Danger and Usefulness effects seem to reflect a general principle underlying human cognition.